Novel lighting technology offers the possibility of improved arthropod integrated pest management (IPM) in artificially lighted crops. This review compiles the current knowledge on how greenhouse pest and beneficial arthropods are directly affected by light, with the focus on whiteflies. The effect of ultraviolet depletion on orientation and colour-coded phototaxis are to some extent studied and utilised for control of the flying adult stage of some pest species, but far less is known about the visual ecology of commercially used biological control agents and pollinators, and about how light affects arthropod biology in different life stages. Four approaches for utilisation of artificial light in IPM of whiteflies are suggested: (a) use of attractive visual stimuli incorporated into traps for monitoring and direct control, (b) use of visual stimuli that disrupt the host-detection process, (c) radiation with harmful or inhibitory wavelengths to kill or suppress pest populations and (d) use of time cues to manipulate daily rhythms and photoperiodic responses. Knowledge gaps are identified to design a road map for research on IPM in crops lighted with high-pressure sodium lamps, light-emitting diodes (LEDs) and photoselective films. LEDs are concluded to offer possibilities for behavioural manipulation of arthropods, but the extent of such possibilities depends in practice on which wavelength combinations are determined to be optimal for plant production. Furthermore, the direct effects of artificial lighting on IPM must be studied in the context of plant-mediated effects of artificial light on arthropods, as both types of manipulations are possible, particularly with LEDs.

Light pollution, the alteration of the natural light levels in the night environment produced by man-made light, is one of the most rapidly increasing threats to the natural environment. The fast growth of the night sky brightness due to light pollution not only is damaging the perception of the starry sky but it is silently altering even the perception of the moonlight nights by mankind. The cyclic alternation between the new Moon's dark sky with thousand of stars and the moonlight sky, less dark but always full of stars among which our satellite moves, is rapidly changing toward a perennial artificial moonlight due to the man-made light wasted in the atmosphere. The Moon periodically will appear inside the same perennially luminous sky from which stars will have almost disappeared. Here we present a map showing artificial moonlight levels in North America and some statistical results.

In this paper, we present the results of a 12-yr campaign devoted to monitoring the sky brightness affected by different levels of light pollution. Different sites characterized by different altitudes and atmospheric transparency have been considered. The standard photometric Johnson B and V bands were used. An extinction measurement was performed for each site and each night, along with a calibration of the instrument. These measurements have allowed us to build sky brightness maps of the hemisphere above each observing site; each map contains up to 200 data points spread around the sky. We have found a stop in zenith sky brightness growth at the two sites where a time series exists. Using zenith sky brightness measurements taken with and without extensive snow coverage, we weighted the importance of direct versus indirect flux in producing sky glow at several sites.

Astronomical observations are increasingly limited by light pollution, which is a product of the over-illumination of the night sky. To predict both the angular distribution of scattered light and the ground-reaching radiative fluxes, a set of models has been introduced in recent decades. Two distinct numerical tools, MSNsRAu and ILLUMINA, are compared in this paper, with the aim of identifying their strengths and weaknesses. The numerical experiment comprises the simulation of spectral radiances in the region of the Canary Islands. In particular, the light fields near the Roque de los Muchachos and Teide observatories are computed under various turbidity conditions. It is shown that ILLUMINA has enhanced accuracy at low elevation angles. However, ILLUMINA is time-consuming because of the two scattering orders incorporated into the calculation scheme. Under low-turbidity conditions and for zenith angles smaller than 70Â° the two models agree well, and thus can be successfully applied to typical cloudless situations at the majority of observatories. MSNsRAu is well optimized for large-scale simulations. In particular, the grid size is adapted dynamically depending on the distance between a light source and a hypothetical observer. This enables rapid numerical modelling for large territories. MSNsRAu is also well suited for the mass modelling of night-sky radiances after ground-based light sources are hypothetically changed. This enables an optimum design of public lighting systems and a time-efficient evaluation of the optical effects related to different lamp spectra or different lamp distributions. ILLUMINA provides two diagnostic geographical maps to help local authorities concerned about light-pollution control. The first map allows the identification of the relative contribution of each ground element to the observed sky radiance at a given viewing angle, while the second map gives the sensitivity, basically saying how each ground element contributes per lumen installed.

In order to study the light pollution produced in the city of Perth, Western Australia, we have used a hand-held sky brightness meter to measure the night sky brightness across the city. The data acquired facilitated the creation of a contour map of night sky brightness across the 2400 km2 area of the city â€“ the first such map to be produced for a city. Importantly, this map was created using a methodology borrowed from the field of geophysics â€“ the well proven and rigorous techniques of geostatistical analysis and modelling.

A major finding of this study is the effect of land use on night sky brightness. By overlaying the night sky brightness map on to a suitably processed Landsat satellite image of Perth we found that locations near commercial and/or light industrial areas have a brighter night sky, whereas locations used for agriculture or having high vegetation coverage have a fainter night sky than surrounding areas. Urban areas have intermediate amounts of vegetation and are intermediate in brightness compared with the above-mentioned land uses. Regions with a higher density of major highways also appear to contribute to increased night sky brightness.

When corrected for the effects of direct illumination from high buildings, we found that the night sky brightness in the central business district (CBD) is very close to that expected for a city of Perthâ€™s population from modelling work and observations obtained in earlier studies. Given that our night sky brightness measurements in Perth over 2009 and 2010 are commensurate with that measured in Canadian cities over 30 years earlier implies that the various lighting systems employed in Perth (and probably most other cities) have not been optimised to minimize light pollution over that time.

We also found that night sky brightness diminished with distance with an exponent of approximately &#8722;0.25 Â± 0.02 from 3.5 to 10 km from the Perth CBD, a region characterized by urban and commercial land use. For distances from 10 out to about 40 km from the CBD the radial variation of night sky brightness steepens to have an exponent value of approximately &#8722;1.8 Â± 0.2. This steepening is associated with land use because vegetation cover increases with further distance from the CBD.